Production of semi conductive integrated circuits and other semi conductive devices from semiconductor wafers typically requires formation of multiple metal layers on the wafer to electrically interconnect the various devices of the integrated circuit. Electroplated metals typically include copper, nickel, gold and lead. Electroplating is effected by initial formation of a so-called seed layer on the wafer in the form of a very thin layer of metal, whereby the surface of the wafer is rendered electrically conductive. This electro conductivity permits subsequent formation of a so-called blanket layer of the desired metal by electroplating in a reactor vessel. Subsequent processing, such as chemical, mechanical planarization, removes unwanted portions of the metal blanket layer formed during electroplating, resulting in the desired patterned metal layer in a semiconductor integrated circuit or micro-mechanism being formed. Formation of a patterned metal layer can also be effected by electroplating.
Subsequent to electroplating, the typical semiconductor wafer or other work piece is subdivided into a number of individual semiconductor components. In order to achieve the desired formation of circuitry within each component, while achieving the desired uniformity of plating from one component to the next, it is desirable to form each metal layer to a thickness which is as uniform as possible across the surface of the work piece. However, because each work piece is typically joined at the peripheral portion thereof in the circuit of the electroplating apparatus (with the work piece typically functioning as the cathode), variations in current density across the surface of the work piece are inevitable. In the past, efforts to promote uniformity of metal deposition have included flow-controlling devices, such as diffusers and the like, positioned within the electroplating reactor vessel in order to direct and control the flow of electroplating solution against the work piece.
In a typical electroplating apparatus, an anode of the apparatus (either consumable or non-consumable) is immersed in the electroplating solution within the reactor vessel of the apparatus for creating the desired electrical potential at the surface of the work piece for effecting metal deposition. Previously employed anodes have typically been generally disk-like in configuration, with electroplating solution directed about the periphery of the anode, and through a perforate diffuser plate positioned generally above, and in spaced relationship to, the anode. The electroplating solution flows through the diffuser plate, and against the associated work piece held in position above the diffuser. Uniformity of metal deposition is promoted by rotatable driving the work piece as metal is deposited on its surface.
However, there is still a high demand in the market to provide amended devices and methods using such new amended devices for the galvanic metal deposition, in particular for the vertical galvanic metal deposition.
In particular, system maintenance, replacements and services require commonly, making use of devices known in the prior art, a high amount of manpower, while it is at the same time very time consuming, which makes the whole process inefficient and costly. Such work leads to a build-down of the entire device for galvanic metal deposition in order to be able to replace essential system components, such as anodes. Thus, during these time-periods, which comprise normally at least one working day, the entire device has to be stopped.